Foot and Ankle cases 9

A 59-year-old female with a longstanding history of bilateral foot pain presents with a recurrent painful callus on her feet and difficulty with ambulation. She describes a history of multiple orthopaedic surgeries in the past addressing her hands, hip, knee, and spine. Weight-bearing radiographs of the foot are obtained (Fig. 5–19A and B).

 

 

Figure 5–19 A, B: AP and lateral radiographs of the foot.

 

What is the most likely underlying diagnosis?

1. Charcot arthropathy

2. Osteomyelitis

3. Posttraumatic arthropathy

4. Inflammatory arthropathy

5. Osteoporosis

 

Discussion

The correct answer is (D), inflammatory arthropathy (specifically rheumatoid arthritis). Figure 5–19 demonstrates the classic radiographic findings of rheumatoid

arthritis (RA), as the forefoot is the most commonly affected region of the foot. RA presents as a symmetric polyarthropathy, with increased deformity with a longer duration of active rheumatoid disease. Patients often develop difficulties with shoeware and metatarsalgia pain from a combination of MTP joint instability, joint synovitis, and hammer toes, followed by ambulation difficulty due to progressive deformity. Charcot arthropathy most commonly affects the midfoot joints, and can also present with joint instability and dislocation.

What is the underlying pathophysiology for this patient’s forefoot deformity?

1. Inflammatory synovial proliferation

2. Factor VIII deficiency with repetitive hemorrhage

3. Synovial crystalline deposition

4. Intra-articular immune complex deposition and antibody formation

5. Neurotraumatic and autosympathetic destruction

 

Discussion

The correct answer is (A). The common forefoot deformity of rheumatoid arthritis includes MTP joint instability due to chronic capsular distention from inflammatory synovium, leading to attenuation of capsuloligamentous attachments. Metatarsophalangeal joint instability progresses to subluxation/dislocation, and is accompanied by tendon contractures of the lesser toes resulting in PIP/DIP deformities including hammer toes. In addition, the plantar fat pad migrates distally with dorsal MTP subluxation and toe contracture, further increasing metatarsalgia symptoms. The incidence of hallux valgus increases with rheumatoid chronicity. Factor VIII deficiency is associated with hemophilic arthropathy, and gout/pseudogout is caused by crystalline deposition of monosodium urate or calcium pyrophosphate dehydrate, respectively.

The patient has had prior treatment by her primary care physician with medical management, callus trimming, and custom orthotics with extra-depth shoes. She continues to report persistent metatarsalgia pain, plantar callus formation, and skin breakdown over her “bunion.”

Surgical treatment for this patient should consist of:

1. Lapidus procedure (first tarsometatarsal arthrodesis), lesser toe hammer toe correction with PIP resection arthroplasty

2. First MTP arthrodesis, lesser toe metatarsal head resections, lesser toe hammer toe corrections

3. First metatarsal double osteotomy and distal soft tissue reconstruction, lesser toe plantar plate repair with hammer toe corrections

4. Transmetatarsal amputation

5. Keller procedure (first MTP resection arthroplasty), lesser toe metatarsal head plantar condylectomy and hammer toe corrections

Discussion

The correct answer is (B), first MTP arthrodesis, lesser toe metatarsal head resections, and lesser hammertoe corrections (Fig. 5–20). Multiple descriptions of this procedure have been reported (Hoffman procedure, Clayton procedure, Fowler procedure) including modifications. With chronic lesser MTP joint subluxation/dislocation, soft tissue reconstruction of the MTP joints traditionally is not performed, and therefore resection arthroplasty of the lesser metatarsal heads is performed to address metatarsalgia symptoms. An appropriate resection cascade of lesser metatarsal lengths is created to allow approximately 1 cm of space for lesser MTP joint decompression. The first metatarsal length is then adjusted to fit the lesser MT cascade, prior to first MTP arthrodesis. Hammer toe correction may be performed with an open procedure addressing the PIP joint for a fixed deformity, or a closed toe osteoclasis for mild/flexible hammer toe deformity. Surgical complications from rheumatoid forefoot reconstruction include recurrent toe deformities, floppy toes, recurrent intractable plantar keratosis, and wound healing problems. Discontinuation of biologic and disease-modifying antirheumatic medications perioperatively in this patient population is currently controversial.

 

 

 

Figure 5–20 Rheumatoid forefoot reconstruction.

 

Objectives: Did you learn...?

 

 

Describe the pathophysiology of rheumatoid arthritis? Describe rheumatoid forefoot deformity?

 

Conservatively treat forefoot deformity?

 

Surgically treat rheumatoid forefoot?